In recent years, light curable substances have received wide-spread acceptance by dentists and patients. Such materials include resins and bonding agents which are applied to the teeth and cured in the presence of intense light. In order to prevent premature activation of the bonding agent, it is important that the material be shielded from excessive ambient light until such time as it is ready to be applied by the dentist. In a modern dental operatory, the dentist often works with a dental assistant. When working with light-curable compositions, the dental assistant customarily holds the container for the materials and opens and closes the material container lid as required to permit the dentist to access the material while minimizing its exposure to ambient light.
One proposed device for conveniently overcoming this problem is disclosed in U.S. Pat. No. 4,991,759 issued to Scharf. The Scharf patent discloses a clam-shell-like container having a hinge permitting the lid to be opened and closed by means of the user's thumb while the container is supported from below by the user's fingers. While the Scharf container may provide certain advantages, it has certain limitations. For instance, the entire hand is occupied in holding and operating the container. This leaves the dental assistant with only the other hand to assist the dentist. A container which could be open and closed readily while enabling the dental assistant to have substantial use of both hands is highly desirable.